Dyestuff of the thioindigo series



55 (within half an hour,

Patented Sept. 4, 1934 DYESTUFF OF THE THIOINDIGO' scams Franz Wieners, Opl'aden Germany, assignor. to

Y General Aniline Works,

Inc., N ew York, N.

a corporation of Delaware No Drawing. Application December 19, "1931,

Serial No. 582,173. In Germany December; 27,; 1930 Claims. (01. 260553) The present invention relates to a. process of preparing symmetrically constituted dyestuifs of the'thioindigo series.- v V In'raccordance with the invention a 5 of the general formula:-' v

compound in which the naphthalene nucleus may be substituted by monovalent. substituents, more particularly alkyl groups, alkoxy groups, nitro groups, or halogen atoms, is caused to react with a sulfur halide, such as sulfur monoor dichloride, sulfur bromide-etc. .It is advantageous, but not necessary to addto the reaction'mixture an organic solvent inert to the starting materials. The reaction performs in two steps. The first reactionalready begins at"lowttempera tures (room temperature or even substantially lower) and finishes with the formation of intermediate products of'unknown structure. intermediate products generally form resinous '25 or smeary compounds, which soon solidify and can then be pulverized to colorless or weakly colored powders. They are difiicultly soluble in, for example, glacial acetic acid, ligroin, but generally soluble in solvents of the aromatic series, such .as benzene, toluene, nitrobenzene, chlorobenzenes etc.

The 7 intermediate products separate from the reaction mixture when a solvent-in which the intermediate products areinsoluble or diflicultly 5 soluble has been applied, or when no solvent at all has been used. Otherwise, the intermeiate products can be separatedfrom the reaction mixture by the additionv ofligroin, glacial acetic acid or the like. Suitable solvents for 40 performing the reaction are, for example, benzene, nitrobenzene, chlorobenzene, ligroin, glacial acetic acid, etc. 7 I

If it is intended to isolate the intermediate products, a temperature substantially above 5 about 80 C. should not be: applied. 1

When heating the intermediate products in the presence or absence of an organic solvent to a temperature above'fabout 100 0., the interm'e'diate products decompose with the formation of symmetrically constituted" vat dyestufis of the thioindigo series. Highertemperatures are operable, and I prefer to apply temperatures between'about'140" and about 250 (3., at which temperatures reaction performs rather quickly for example).

These tone are dissolved in 50 parts dichlorobenzene and the equimolecular quantity If a sol-vent is applied in thissecondstep of the advantageous to use a rather high boiling one, such as naphthalene, nitrobenzene, chlorobenzene, ortho dichlorobenzenes etc.

Obviously, it is not necessary to isolate the intermediate products above mentioned, but the formation 'of thedyestufis of the thioindi'go series may be combined with the formation of the intermediate products to one step of working. In this case an organicsol-vent boiling above ab'Qut IGO" C. and being inert to the starting materials is advantageously-applied', and after the addition of the sulfur halide thereaction mixture is slowly heated to above about 100 C., advantageously to, a temperaturebetween about 140 and about 250 C. The dyestuffs formed separate fromthe reaction mixture, after cooling in most cases, otherwise the reaction may be worked upbythe addition of a solvent inwhich the dyestuffs are'ins'oluble or diificultly soluble, filtering and washing. 7 V The following examplesillustrate the invehtion, without however, restricting it thereto-:

4 Erample 1 "56 parts by weight of alpha-naphthylmethylketone are mixed with the equimolecular quantity or somewhat more of sulfur monochloride in 1-50 parts by weight of nitrobenzene and heated to 90 C. The reaction soon-commences and when it subsided, the temperature is'raised to about 140450 0., and this'ternperature ismaintained for some hours. Needles ofzl-naphthoxythiophene-indigo soon begin to=separate. After completion of the reactiomthe mixture is allowed to cool, the dyestufi filtered by suction and washed with nitrobenzene and then with a little alcohol. The dyestufi possesses-theproperties describedby Friedlander in Annalen 388, page 16. The nitrobenzene may be replacedby glacial acetic acid, chlorobenzene, trichlorobenzene and other solvents with a similar result.

, Example 2 10 parts by weight or beta-naphthylmethylkebyweight of orthoof sulfur monochlorideis added. The reaction mixture is heated to 60 C., until the-first reaction ceases, and the temperature is then quickly raised to I60-170" C. The dyestuff-soon' begins to separate from the reaction mixture" in" long needles while still hot. When the precipitation no longer increases, which is the case after about formationcf thioindigoait is obviously upon-the dyestuiff l-methylketone are weight of glacial acetic acid and one hour, the mixture is allowed to cool and fil tered by suction. After washing with orthodichlorobenzene and a little alcohol, shining reddish-brown needles of the very pure dyestuff remain. On account of its properties the dyestuif is presumably identical with the 1.2-naphthoxythiophene-indigo described by Friedlander in Annalen 388, page 18.

Example 3 i 28 parts by weight of 2-acetylnaphthalene are dissolved while stirring in about 100 parts by weight of ligroin and this solution is mixed with the calculated quantity of sulfur 'monochloride. After about /2 to 1 hours a light separate, the formation stirring. After about 24 hours the separation is finished. The excess of the ligroin is filtered off or decanted, the compound washed several times with ligroin, and the brittle mass finally obtained is pulverized. ;The light; powder obtained is an hour into 250 stirredin portions within of 7 parts by weight of nitrobenzene at 200 C., whereis formed with vigorous foaming (separation of HCLHZS and-H O) This dye- ,stuffis identical withthat obtained according to Example 2.. The working up is effected according to the method described in Example 2.

In the same'manner a mixture of alphaand beta-naphthylmethyll etone can be, worked up,

which mixturelis obtained by condensing naphthalene in carbon disulfide, benzene, dichlorobenzene or another similar solvent with acetylchloride, by means of anhydrous aluminium chloride. 0

In this case a mixture of the dyestuffs obtained according to Examples 1 and 2 is formed.

I Example 4 30 parts by weight of l-methcxynaphthalenedissolved in parts by mixed while stirring with the calculated quantity of sulfur mono- ,chlorideat a temperature of about 20 C. Stirring is continued as long as possiblathat is, as

,long as the formation of a brittle resin, which soon begins, permits the stirring of the reaction mixture. Thelatter is then allowed to stand overnight, and the intermediate product is isolated and pulverized as; described inExample 3, whereupon itis stirred into 250 p irtsby weight of nitrobenzene at 200 C. within 1 hour. Stirring is continuedfor another hour, whereupon the dyestuff is obtained by filtering with suction at a temperature of 50 C. in beautiful orange brown needles. The dyestuff is washed with some pyridine and alcohol and dried. I

a The dyestufl dissolves .in sulfuric acid with a bluish-green coloration. From this solution it is precipitated with water in yellowish-brown flakes.

Acetyl-l-chlornaphthalene treated in the same 1 manner yields a similar. somewhat darker brown dyestuif. I

In the above examples the naphthalene derivatives may be substituted, for example, by the product obtainable by reacting upon l-me'thylnaphthalene with acetylchloride in the presence of aluminium chloride, or by the product obtainable by nitrating 1- or 2- acet'yl naphthalene, whereby thioindigos substituted byalkylor nitro resin begins to" of which prevents further wherein the V naphthalene gen atoms, with a sulfurence of anorganic solvent temperature between wherein the naphthalene nucleus may be substitutedby alkyl-, alkoxy-, nitro groups or halogen atoms, with a sulfur halide to a temperature above about 100 C.

2. The process which comprises heating a compound of thegeneral formula wherein the naphthalene nucleus maybe substituted by .alkyl-, alkoxy:,.nitro groups. or halogen atoms, with a sulfur halide to a temperature above 3. The process which comprises heating a compound of the general formula .CO.CH3

nucleus may be subnitro groups or halohalideto a temperature between about .140 and about 250C. in the presbeing inert to the starting materialsand having a boiling point above about 100 C. 1. I

4. The process whichcomprises heating a compound of the general formula.

stituted byalkyl-,, alkoxy-,

wherein one a: means hydrogen and the other :1: the grouping' CQCHa'with asulfur halide to a about 140 and about 250 C. in thepresence of an organicsolvent being inert to the starting materials and havinga boiling pointaboveaboutlOO" C.

' i 5. The process which comprises heating a compoundof the general formula ing inert to the starting materials and having a,

boiling point above about 100C.

wrENEas.

:0 means hydrogen'iand. the other $3140 

